Dry aeolian dust accumulation in rocky deserts: ­a medium‐term field experiment based on short‐term wind tunnel simulations

The spatial pattern of medium‐term (a few months) dry aeolian dust accumulation in rocky deserts is predicted using short‐term deposition and erosion experiments in a wind tunnel. The predictions are tested in a field experiment set up in the northern Negev Desert of Israel. The results show that superimposing wind tunnel deposition and erosion maps usually leads to correct predictions of medium‐term dust accumulation. The predictions are somewhat less confident near the inflection lines of windward hillslopes, where small‐scale irregularities in the local topography make it difficult to locate the exact position of the areas of little accumulation. Elsewhere in the topography predictions are good, and the method works satisfactorily. Highest accumulation occurs on concave windward slopes and, to a lesser extent, on slopes parallel to the wind. Little accumulation occurs on the convex windward slopes and in dust separation bubbles. The smallest accumulation rates are observed immediately upwind of the top of pronounced hills and on leeslopes. The rate of dry dust accumulation measured during the field experiment varied from 17 to 93 g m⁻² a⁻¹, depending on the topographic position of the accumulation plots. For most plots, it was of the order of 30–60 g m⁻² a⁻¹. Copyright © 2000 John Wiley & Sons, Ltd.